Compact adjustable pressure relief valve

Abstract

The utility model relates to a kind of compact adjustable overflow valve, including valve shell, valve shell is the hollow cavity of two ends opening, overflow hole is set up on valve shell, the front end opening of valve shell, by interference assembly mode, valve seat is installed, inflow passage is set up on valve seat;Valve seat is movably connected with lift valve core, spring is set on the stem of lift valve core, the stem tail end of lift valve core is set with valve sleeve;Piston is installed outside valve sleeve, the rear end opening of valve shell is connected with screw plug by screw thread mode, main plugging mechanism is distributed between the rear end opening side wall of valve shell and the outer wall of screw plug;Valve shell is distributed with vice plugging mechanism. Thus, two kinds of optional pressure regulating mode of gasket or adjusting nut are used, spring pre-compression amount can be conveniently adjusted by changing gasket thickness or rotating adjusting nut, meet the differentiating needs of different hydraulic systems to overflow pressure. Meanwhile, the adjustment process does not need complicated disassembly, adapts to a variety of working condition applications.

Description

Technical Field

[0001] This utility model relates to an overflow valve, and more particularly to a compact adjustable overflow valve. Background Technology

[0002] In the existing technology, for hydraulic transmission systems, the relief valve is a key component for maintaining stable system pressure. Its sealing performance, pressure regulation accuracy and service life directly affect the operational reliability of the entire hydraulic system.

[0003] To address the sealing issues of relief valves, various sealing structure designs have emerged, such as the dual-sealing pair disclosed in Chinese patent application CN101135397A for a mixed-flow relief valve. This design utilizes a combination of upper and lower sealing pairs, employing the cooperation of sealing rings and sealing collars to achieve sealing, thus improving sealing reliability to some extent. However, this structure does not optimize the axial restraint of the sealing elements, making it prone to leakage problems caused by seal displacement during long-term, high-frequency operation.

[0004] Meanwhile, Chinese patent CN213017805U discloses a relief valve structure. It achieves pressure control through the cooperation of a spring and piston. However, the layout of its adjusting components and sealing structure is relatively loose, resulting in a large overall valve body size, making it difficult to adapt to the installation requirements of compact hydraulic systems. Furthermore, traditional adjusting methods often use a single shim or fixed nut structure, lacking sufficient adjustment flexibility and unable to quickly adapt to changes in pressure requirements under different operating conditions.

[0005] In addition, the valve core and seat of the relief valve are prone to wear due to frequent contact during long-term opening and closing, which leads to a decrease in sealing performance and a reduction in pressure control accuracy.

[0006] In view of the above-mentioned shortcomings, the designer actively researched and innovated in order to create a compact adjustable relief valve that would have greater industrial application value. Utility Model Content

[0007] To solve the above-mentioned technical problems, the purpose of this utility model is to provide a compact adjustable overflow valve.

[0008] This utility model discloses a compact adjustable overflow valve, comprising a valve housing, which is a hollow cavity open at both ends, with an overflow hole on the valve housing. The valve housing has an inlet channel at its front end opening, and a valve seat is mounted thereon via an interference fit. A lifting valve core is movably connected to the valve seat, a spring is sleeved on the rod of the lifting valve core, and a valve sleeve is sleeved on the tail end of the rod. A piston is mounted outside the valve sleeve. A screw plug is threadedly connected to the rear end opening of the valve housing, and a main sealing mechanism is distributed between the side wall of the rear end opening of the valve housing and the outer wall of the screw plug. A secondary sealing mechanism is distributed outside the valve housing. Both the main and secondary sealing mechanisms include O-rings, and a retaining ring is sleeved on one side of each O-ring.

[0009] Furthermore, in the aforementioned compact adjustable relief valve, the valve seat has conical valve ports distributed on it, and the corresponding position of the lifting valve core has a conical head distributed on it, the conical head being adapted to the shape of the conical valve ports; the rod of the lifting valve core extends into the stepped hole of the valve sleeve; the bottom of the piston extends with a stop edge, and a stop step is distributed on the inner side of the valve housing, and when in the blocking state, the stop edge contacts the stop step.

[0010] Furthermore, in the aforementioned compact adjustable overflow valve, the outer side of the screw plug has an M20*1.5 external thread, and the screw plug is provided with adjusting concave holes, which are hexagonal concave holes or rectangular concave holes.

[0011] Furthermore, in the aforementioned compact adjustable relief valve, a contact guide rod is installed at the rear end of the valve sleeve. The contact guide rod is a polytetrafluoroethylene rod, and the rod portion of the lifting valve core contacts the contact guide rod.

[0012] Furthermore, in the aforementioned compact adjustable relief valve, a gasket is fitted at the front end of the valve sleeve, and one end of the spring contacts the gasket; or, an adjusting nut is installed at the front end of the valve sleeve, and the adjusting nut contacts the gasket.

[0013] Furthermore, in the aforementioned compact adjustable relief valve, the O-ring is either a nitrile rubber ring or a fluororubber ring.

[0014] Furthermore, in the aforementioned compact adjustable relief valve, the inlet channel has wear-resistant rings distributed on the contact end face corresponding to the lifting valve core, and the wear-resistant rings are Orkot composite wear-resistant rings.

[0015] Furthermore, in the aforementioned compact adjustable relief valve, the outer wall of the valve housing is provided with connecting external threads.

[0016] By means of the above solution, this utility model has at least the following advantages: 1. The dual sealing design of the main and auxiliary sealing mechanisms, combined with the O-ring and retaining ring combination structure, effectively prevents hydraulic oil leakage. An Orkot composite wear-resistant ring is installed on the tapered mating surface between the valve core and the valve seat to reduce wear on the sealing surface and significantly extend the service life of the sealing assembly.

[0017] 2. The system offers two pressure adjustment options: shims or adjusting nuts. The spring precompression can be easily adjusted by changing the shim thickness or rotating the adjusting nut, meeting the varying overflow pressure requirements of different hydraulic systems. Furthermore, the adjustment process requires no complex disassembly, making it suitable for a wide range of operating conditions.

[0018] 3. The mating structure between the piston stop edge and the valve body stop step effectively limits the maximum displacement of the valve core, preventing fatigue damage to the spring due to excessive compression. The PTFE contact guide rod at the rear end of the valve sleeve provides contact buffering, reducing the risk of valve core jamming and ensuring the stability of valve operation.

[0019] 4. The entire valve body adopts an integrated design, with each component assembled compactly through interference fits and threaded connections, occupying little installation space. Key wear parts such as O-rings and gaskets adopt standardized structural designs, facilitating disassembly and replacement and reducing later maintenance costs and difficulties.

[0020] The above description is only an overview of the technical solution of this utility model. In order to better understand the technical means of this utility model and to implement it in accordance with the contents of the specification, the preferred embodiments of this utility model are described in detail below with reference to the accompanying drawings. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the structure of a compact adjustable relief valve.

[0022] The meanings of the labels in the figures are as follows.

[0023] Detailed Implementation The specific embodiments of this utility model will be described in further detail below with reference to the accompanying drawings and examples. The following examples are used to illustrate this utility model, but are not intended to limit its scope.

[0024] like Figure 1This compact adjustable relief valve includes a valve body 3, a hollow cavity with openings at both ends, and an overflow hole 11 on the side wall of the valve body 3. The overflow hole 11 is used to release hydraulic oil when the internal pressure reaches a set value. Its unique feature is the presence of external threads 13 on the outer wall of the valve body 3. These threads are used to securely connect the compact adjustable relief valve to the pipelines or equipment of an external hydraulic system, ensuring installation stability. This avoids the vibration or loosening that can occur during use due to large hydraulic fluctuations in traditional direct-insertion methods. During implementation, the valve seat 1 is fixedly installed at the front opening of the valve body 3 using an interference fit (or threaded connection, etc.). The interference fit ensures the sealing performance between the valve seat 1 and the valve body 3, preventing hydraulic oil leakage from the mating gap. An inlet channel is provided through the valve seat 1, which is the only channel for external hydraulic oil to enter the valve. A conical valve port is provided on the side of the valve seat 1 facing the interior of the valve body 3. A lifting valve core 2 is movably connected to the valve seat 1. A conical head is integrally formed at the corresponding position of the lifting valve core 2 facing the valve seat 1. The shape of the conical head is adapted to the conical valve port of the valve seat 1. In this way, when the lifting valve core 2 moves towards the valve seat 1, the conical head can be inserted into the conical valve port to block the inflow channel. When the lifting valve core 2 moves away from the valve seat 1, an annular gap is formed between the conical head and the conical valve port. External hydraulic oil can enter the interior of the valve body 3 through this gap and finally be discharged through the overflow hole 11. Meanwhile, a wear-resistant ring is embedded at the contact end face of the conical head of the lifting valve core 2 corresponding to the inlet channel of this utility model. The wear-resistant ring is an Orkot composite wear-resistant ring. Orkot composite wear-resistant material has excellent wear resistance and impact resistance, which can effectively reduce the wear caused by long-term contact and collision between the lifting valve core 2 and the valve seat 1, extend the service life of both, and ensure the sealing accuracy of the sealing surface. In a preferred embodiment of this invention, for hydraulic and reset purposes, a spring 8 is fitted onto the rod portion (i.e., the end furthest from the conical head) of the lifting valve core 2. This spring 8 is a cylindrical helical compression spring, and its elastic coefficient can be selected according to the set overflow pressure of the relief valve. Simultaneously, a valve sleeve 4 is fitted onto the tail end of the rod portion of the lifting valve core 2. The valve sleeve 4 has a stepped hole, and the end of the rod portion of the lifting valve core 2 furthest from the conical head extends into the stepped hole of the valve sleeve 4. A contact guide rod 12, made of polytetrafluoroethylene (PTFE), is installed within the stepped hole of the valve sleeve 4, providing appropriate buffered contact with the tail end face of the lifting valve core 2 rod.

[0025] Looking further, a piston 5 is fitted onto the outer side of the valve sleeve 4, and the piston 5 and valve sleeve 4 fit together. A stop edge extends integrally from the bottom of the piston 5. Correspondingly, a stop step is integrally formed on the inner wall of the valve housing 3. When the overflow valve is in a blocked state (i.e., not overflowing), the stop edge of the piston 5 contacts the stop step of the valve housing 3. This contact fit limits the movement limit of the piston 5 towards the front end of the valve housing 3, thereby indirectly limiting the movement position of the lifting valve core 2 through the valve sleeve 4 and spring 8, ensuring the sealing reliability of the conical head and the conical valve port. Simultaneously, a gasket 7 is fitted at the front end of the valve sleeve 4. The gasket 7 is made of metal, such as a copper or steel gasket, and one end of the spring 8 contacts the end face of the gasket 7 facing the spring 8. The presence of the gasket 7 serves two purposes: firstly, it prevents the spring 8 from skewing during compression and reset, ensuring that the spring force of the spring 8 always acts along the axial direction of the lifting valve core 2. Secondly, by replacing the gaskets 7 with different thicknesses, the initial compression of the spring 8 can be adjusted, thereby adjusting the initial force exerted by the spring 8 on the lifting valve core 2, ultimately meeting the different requirements of different hydraulic systems for overflow control pressure. In practical implementation, the valve body 3 has an internal thread machined on the inner side of its rear end opening, and a plug 6 is installed in this opening via a threaded connection. Simultaneously, the outer wall of the plug 6 has an M20*1.5 external thread, which perfectly matches the internal thread of the valve body 3's rear end opening. Rotating the plug 6 allows for axial position adjustment within the valve body 3's rear end opening. Furthermore, an adjustment recessed hole is provided at the end of the plug 6 furthest from the valve body 3's interior. This adjustment recessed hole can be either hexagonal or rectangular. Thus, when it is necessary to rotate the plug 6, a hex wrench (corresponding to the hexagonal recessed hole) or a flathead wrench (corresponding to the rectangular recessed hole) can be inserted into the adjustment recessed hole for convenient tightening of the plug 6.

[0026] During implementation, to further ensure the sealing performance of the connection between the valve body 3 and the plug 6, a main sealing mechanism is distributed between the rear opening sidewall of the valve body 3 and the outer wall of the plug 6. Simultaneously, a secondary sealing mechanism is also distributed on the outer wall of the valve body 3. For ease of implementation, the main and secondary sealing mechanisms are structurally identical, both including an O-ring 9 and a retaining ring 10. The O-ring 9 is fitted onto the outer wall of the plug 6 or the corresponding mounting groove of the valve body 3, and the retaining ring 10 is fitted onto one side of the O-ring 9 to axially limit its movement, preventing axial displacement and failure under hydraulic pressure. Furthermore, the O-ring 9 can be selected as a nitrile rubber ring or a fluororubber ring. Specifically, when this compact adjustable relief valve is used in a hydraulic system using mineral hydraulic oil as the medium, a nitrile rubber ring is selected, as nitrile rubber has good oil resistance to mineral hydraulic oil. When this compact adjustable relief valve is used in high-temperature conditions, such as hydraulic systems with an ambient temperature above 80°C, a fluororubber ring should be selected. Fluororubber has excellent high-temperature resistance, which can ensure good sealing performance even at high temperatures.

[0027] Regarding the assembly process of this utility model: First, the wear-resistant ring is embedded in the contact end face of the inlet channel of the valve seat 1. Then, the valve seat 1 is press-fitted into the front opening of the valve body 3 through an interference fit. Next, the conical head of the lifting valve core 2 is oriented towards the conical valve port of the valve seat 1, the rod of the lifting valve core 2 is passed through the spring 8, and the tail end of the rod of the lifting valve core 2 is inserted into the stepped hole of the valve sleeve 4. Then, the gasket 7 is fitted onto the front end of the valve sleeve 4, ensuring that one end of the spring 8 is in contact with the gasket 7. Install the contact guide rod 12 at the rear end of the valve sleeve 4, and then fit the piston 5 onto the outside of the valve sleeve 4, ensuring that the stop edge of the piston 5 faces the rear end of the valve housing 3. Next, assemble the O-ring 9 and the retaining ring 10 to their corresponding positions on the main and auxiliary sealing mechanisms. Then, screw the plug 6 into the rear opening of the valve housing 3 through the M20*1.5 external thread until the inner end face of the plug 6 contacts the other end of the spring 8, and adjust the screwing depth of the plug 6 according to the set pressure. Finally, install this compact adjustable relief valve into the external hydraulic system through the connecting external thread 13 on the outer wall of the valve housing 3, completing the assembly. The working principle of this utility model is as follows: Blocked state: External hydraulic oil enters the valve through the inlet channel of valve seat 1. At this time, the elastic force of spring 8 pushes the lifting valve core 2 to move towards valve seat 1, so that the conical head of the lifting valve core 2 is embedded in the conical valve port of valve seat 1, the inlet channel is blocked, and hydraulic oil cannot enter the valve body 3.

[0028] Overflow state: When the pressure of the external hydraulic oil increases to the set overflow pressure, the thrust of the hydraulic oil on the conical head of the lifting valve core 2 is greater than the elastic force of the spring 8, pushing the lifting valve core 2 to move away from the valve seat 1. A gap is formed between the conical head and the conical valve port. The hydraulic oil enters the valve body 3 through this gap and then flows out through the overflow hole 11 of the valve body 3 to achieve pressure relief.

[0029] Reset state: When the pressure of the external hydraulic oil drops below the set pressure, the elastic force of the spring 8 is greater than the thrust of the hydraulic oil on the lifting valve core 2, pushing the lifting valve core 2 to move towards the valve seat 1, and the conical head is re-embedded in the conical valve port, restoring the sealing state.

[0030] Furthermore, the directions or positional relationships described in this utility model are based on the directions or positional relationships shown in the accompanying drawings. They are only for the purpose of facilitating the description of this utility model and simplifying the description, and are not intended to indicate or imply that the device or structure referred to must have a specific orientation, or to operate in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0031] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present utility model, and these improvements and modifications should also be considered within the protection scope of the present utility model.

Claims

1. A compact adjustable relief valve, comprising a valve housing (3), wherein the valve housing (3) is a hollow cavity open at both ends, and an overflow hole (11) is provided on the valve housing (3), characterized in that: The valve body (3) has a valve seat (1) installed at its front end opening by interference fit. The valve seat (1) has an inlet channel. A lifting valve core (2) is movably connected to the valve seat (1). A spring (8) is sleeved on the rod of the lifting valve core (2). A valve sleeve (4) is sleeved on the tail end of the rod of the lifting valve core (2). A piston (5) is installed on the outside of the valve sleeve (4). A screw plug (6) is connected to the rear end opening of the valve body (3) by thread. A main sealing mechanism is distributed between the side wall of the rear end opening of the valve body (3) and the outer wall of the screw plug (6). A secondary sealing mechanism is distributed outside the valve body (3). Both the main sealing mechanism and the secondary sealing mechanism include an O-ring (9). A retaining ring (10) is sleeved on one side of the O-ring (9).

2. The compact adjustable relief valve according to claim 1, characterized in that: The valve seat (1) is provided with conical valve ports, and the corresponding position of the lifting valve core (2) is provided with conical heads. The conical heads are adapted to the shape of the conical valve ports. The rod of the lifting valve core (2) extends into the stepped hole of the valve sleeve (4). The bottom of the piston (5) extends with a stop edge, and the inner side of the valve housing (3) is provided with a stop step. When it is in a blocked state, the stop edge is in contact with the stop step.

3. The compact adjustable relief valve according to claim 1, characterized in that: The screw plug (6) has an M20*1.5 external thread on the outside. The screw plug (6) has an adjustment concave hole distributed on it. The adjustment concave hole is a hexagonal concave hole or a rectangular concave hole.

4. The compact adjustable relief valve according to claim 1, characterized in that: The valve sleeve (4) is equipped with a contact guide rod (12) at its rear end. The contact guide rod (12) is a polytetrafluoroethylene rod, and the rod part of the lifting valve core (2) is in contact with the contact guide rod (12).

5. The compact adjustable relief valve according to claim 1, characterized in that: A gasket (7) is fitted on the front end of the valve sleeve (4), and one end of the spring (8) contacts the gasket (7); or, an adjusting nut is installed on the front end of the valve sleeve (4), and the adjusting nut contacts the gasket (7).

6. The compact adjustable relief valve according to claim 1, characterized in that: The O-ring (9) is a nitrile rubber ring or a fluororubber ring.

7. The compact adjustable relief valve according to claim 1, characterized in that: The inflow channel has wear-resistant rings distributed on the contact end face of the lifting valve core (2), and the wear-resistant rings are Orkot composite wear-resistant rings.

8. The compact adjustable relief valve according to claim 1, characterized in that: The outer wall of the valve body (3) is provided with connecting external threads (13).

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